Explosively actuated flaring tool



July 6, 1965 R. T. cATLlN ETAL EXPLOSIVELY ACTUATED FLARING' TOOL Original Filed Aug. 10, 1960 8 Sheets-Sheet l www July 6, 1965 R. T. cArLlN ETAL EXPLOSIVELY ACTUATED FLARING TOOL Original Filed Aug. l0. 1960 Af 5 m mkv whw mnu? M we 55 m w mzf A m f f 77. n w In l! NS mwmn //7 /7 /X/y. x f oewm AJ. \`f f, Biff, Q NQ @Q Q gf@ QS Y (bf M, QW Ml E. m. KSN mm d m am mm emm'i,

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July 6, 1965 R.T.cAT| 1N ETAL 3,192,758

EXPLOSIVELY ACTUATED FLARING TOOL Original Filed Aug. l0, 1960 8 Sheets-Sheet 4 IN VEN TORS July 6, 1965 R. T. CATLIN ETAL 3,192,758

EXPLOSIVELY ACTUATED FLARING TOOL Tiq. l E .504 3Q July 6, 1965 R. T. cATLlN ETAL.

EXPLOSIVELY ACTUATED FLARING TOOL July 6, 1955 R. T. cA'rLlN ETAL EXPLOSIVELY ACTUATED FLARING TOOL Original Filed Aug. 10, 1960 8 Sheets-Sheet '7 E ,www5 mxmw M TJJO. N 7a2/Tmt ii y 5%@ rmLl @AA m MSM www b@ E Al, .m m

July 6, 1965 n.1'. cATLlN ETAL EXPLOSIVELY ACTUATED FLARING TOOL Original Filed Aug. l0, 1960 8 Sheets-Sheet 8 www QwN NE s mi? u V/:JS r N /...7 1 JJ@ A ami? @HRK

United States Patent O M' 3,132,753 EXPLQSVELY AQTUATED FLAREQS TQQL Robert T. Catlin, r"runn'nill, and Arthur Landa, Shelton, Conn., Robert 3. Service, ilion, NX., and Robert t), Swain, Trumbull, Conn., assignors to Remington Arms Company, lne., Bridgeport, Conn., a corporation of Delaware @riginal application Ang. il?, i959, Ser. No. 48,754, now Patent No. 3,125,636, dated M'ar. lll, i964. Divided and this application Get, l, i962, No. 23l,398 The portion of the term of the patent subsequent to Mar. 3i, i981, has been diselaimed 22 Claims. (Cl. 7Z--316) This application is a division of our copending application Serial No. 48,764, filed August 10, 1960, issued as U.S. Patent No. 3,126,630 on March l0, 1964.

This invention relates to tools for shaping apertures .in metal and the like. More particularly the invention relates to explosively actuated flaring tools for providing tlared shape to the metal at .the end .of metal tubing or .at similar apertures.

Where a flare is to be provided at the end of a metal conduit, .and rather than employing usual hammer-driven or 4advancing screw thread manual type equipment, one conventional tube flaring method involves the use of an electrically driven machine to roll rather than impress, the end of the tube into the desired tapered `flare configuration. This machine, which is usually relatively large and weighs several hundred pounds, is mounted on a cabinet stand or the like and .has an electrically rotated head which mounts a tapered flaring cone. The flaring cone revolves freely on an eccentric-ally mounted bearing and, when brought into contact with the end of the tube which is held in piace in a mechanical or pneumatic tube clamping device, rolls around the circumference of the tube to press it against a backing die so as .to form the desired flared end configuration. ln spite of the benefit afforded by elimination of such manu-al labor, when the machine is used to flare tubes made of certain metals, the tube material tends to become work-hardened as the `roll-flaring operation progresses and, in many cases, the flared end will rupture before it has been completely formed. lt is .thought .that this diculty can be largely overcome by increasing the speed with which the flare is completely formed, such as by forming the flare substantially instantaneously in a shock-type operation rather than by roll forming, so as to bypass the work hardening effect. Moreover it appears that such conventional manual or electric tube .flaring equipment a-s has been used is limited with respect to its effective capability of providing flared ends on tubes within the general size Irange of from 1/s inch to 2 inches in diameter. However, because of recent developments in certain fields wherein tube flaring operations are involved, the trend is towards use of larger diameter tubing, and towards the use of tubes made of harder materials, such .as stainless steel. Thus for all of these reasons, the need for appropriate power driven flaring equipment has increased.

Where explosively actuated tools have been used, in :many cases they have been dangerous to handle because they .are subject to severe recoil and counter-recoil and may twist or otherwise move erratically during operation. Such undesirable tool action may be due to inadequate provision for 4dampening of reaction forces which .are set up in response to explosion of the powder charge, and to the construction and arrangement 4of tool parts such .as the trigger and bolt firing mechanisms, and other elements. Moreover, such tools as have been used sometimes are difficult to accurately position against the work for effective hole shaping, are sometimes limited in application to perhaps a single type of work and, insofar as the inventors hereof lare aware, do not provide effective selfy alegres Patented July 6, 1965 lCe` retraction of the -llaring instrument from the metal. Furthermore, .some explosively actuated tools break down during use, and this is believed vto be due t-o inadequate dampening or braking of the piston driver element upon firing the tool, the element Vdestroying itself or the tool by repeated impacts against abutting elements within the barrel.

The present invention provides an explosively actuated .flaring tool which overcomes these and other disadvantages. It is portable .and does not require an outside power source. It is light in weight, economical and safe in operation. Only one .hand need be used to position and tire the tool, and it will be found that recoil and counter-recoil are hardly noticeable to the operator. The tool will have .almost no tendency to twist or otherwise move erratically during use. Moreover, tubes of relatively large diameter .and of relatively hard material may be effectively flared at their ends in simple, convenient manner without danger of rupturing the tube end.

Generally describing the operation of t-he tool which is .here provided, a small caliber blank cartridge is fired within the device to drive the flaring instrument into contact with .the workpiece. As will be seen, the flaring instrument will be immediately and .automatically retracted at the end of its stroke, yet the operator will realize very little tool kick during use. The tool has a barrel section linearly .aligned and attached to a reeiver section which mounts a bolt firing mechanism.

The tool is arranged so that, by a simple, counterclockwise twisting and withdrawal motion, the bolt mechanism .may be drawn away from .the barrel section, to expose 4an axially aligned cartridge chamber at the receiver end of the barrel section wherein the small caliber, blank cartridge power load is inserted. After -inserting the cartridge, the bolt mechanism is moved forward and rotated in clockwise direction .to close and lock .the cartridge chamber. Alternatively, it may be rotated about forty-live degrees to a safety position in which it is impossible to re the tool but in which the bolt cannot be accidentally withdrawn, or it may be rotated a substantially greater amount, about ninety degrees, to the `firing position of the tool.

When the .tool has been loaded and is positioned for tiring, the operator either simply inserts the workpiece in an integrated work-holding jig 1of the tool, or moves the tool against the workpiece, depending upon the tool modifica-tions employed, and lires it. The pressure of the expanding gases from the exploded lcartridge impels a slidable piston within the barrel section, to which the flaring instrumentality is attached, a predetermined short distance forward t0 move the instrument into sudden impact with .the workpiece. The tool provides automatic, ful-l retraction and repositioning of the flaring instrument immediately after firing, to its initial, pre-tiring position ready for the next operation. The entire operation is quick, safe, and instantaneously effective to accurately provide a flared configuration surrounding a workpiece aperture by a single tiring of the tool.

The tool is designed to propel the flaring instrument forward the desired distance with just the proper amount of power .required to properly .flare the aperture edges, yet not distort the surrounding metal, and thereafter to fully retract the instrument, .taking into consideration the amount of energy which is absorbed by the workpiece. Furthermore, it will be found that recoil and counter recoil :of the tool are hardly noticeable to Ithe operator, and that the tool will have almost no tendency to twist or otherwise move erratically lduring use. This substantial elimination of tool "kick assures greater operator overall elciency .and accuracy in use.

Referring more particularly to the preferred form of tool construction, the invention provides a novel piston buffer system within the barrel section which, prior to firing the tool, extends effectively the full length of the barrel. The butter assembly generally consists of a stack of buffer rings of elastically deformable material, such as neoprene, polyurethane or the like, alternating with interposed metal impact rings. The assembly surrounds that portion of the piston rod which is normally disposed within the barrel, and extends between retaining means on the muzzle-facing end of the piston and a centrally apertured abutment wall at the muzzle end of the barrel so as to be compressed between the piston and the abutment wall as the piston is impelled towards the muzzle end by the explosion of the powder charge. The elastically deformable buer rings have diameter somewhat less than the internal diameter of the barrel and are relatively thick, so that during compression, they expand into contact with the barrel wall. As will be seen, the buffer system provides controlled braking of the piston element during its forward travel. Because of the resilient nature of the buffer rings, the system also causes repositioning of the piston to its normal location with its receiver-facing end at the receiver end of the barrel, and therefore full retraction of the attached daring instrument instantaneously after the flare has been formed. Modifications of the form, characteristics and arrangement of the buffer rings, as will be described, will provide modified piston braking effects in the tool, yet instantaneous retraction of the aring instrument upon completion of the tiring cycle. Further modifications in the buffer system, as will be seen, will effect accurate determination of the length of stroke of the flaring instrument, yet achieve all of the other desired tool characteristics.

A novel, sleeve type tiring bolt retractor is also provided which materially contributes to effective operation of the tool. Normally, bolt action guns and bolt action explosively actuated tools have a relatively heavy metal lever extending outwardly from the bolt and receiver section which the operator grasps and lifts to withdraw the bolt and open the breech or" the device. In the present invention, this extending lever is eliminated and replaced by a lightweight cylindrical sleeve, of plastic or the like, which sleeves around the receiver section of the tool in relatively close fitting relation when the bolt is in its closed position. This novel sleeve type bolt retractor is more durable than is the lever type, being not susceptible to breaking off by accidental impact. Further, and aside from its light weight which causes a reduction in the total inertia of the tool under dynamic conditions of tiring, the sleeve bolt retractor eliminates the setting up of unbalanced inertia forces during tool tiring which normally would occur due to the radially extending, relatively heavy moment arm of a lever were such provided. These forces would cause twisting or other erratic movement of the tool upon tiring.

In a preferred construction of the tool the trigger mechanism does not include a trigger of the conventional, finger-operated type ordinarily found in guns and the like. lt has been found that such conventional triggers, which do not include the features of the modified form of linger-operated trigger hereinafter to be described, transmit a considerable amount of tool recoil and counterrecoil to the finger or hand of the operator, causing soreness and resulting fatigue in the hand. Instead, the pre- -ferred construction provides a hand-pressure actuated trigger lever which extends substantially parallel to the barrel towards the muzzle end of the tool. lt pivots at the general location of the junction between the barrel and receiver sections, and figuratively speaking wraps around the tool to the other side where it is coupled to a longitudinally extending sear link which is moved upon trigger actuation to activate the tiring mechanism of the tool. In explosively actuated tools, it has been found that this novel trigger mechanism not only overcomes the referred to diculties of the conventional mechanisms, but also promotes the ease with which the tool is operated.

In a modified construction, a more conventional linger- Operated trigger mechanism is provided also to eliminate the referred to tool-firing reaction ditlicultiesy which can be traced primarily to counter-recoil effects. The trigger link and trigger arrangement includes a trigger cushioning spring, as will be described, which dampens the counter-recoil forces in the tool which would act against the finger to cause soreness and resulting fatigue in the hand of the operator. Furthermore, it should be noted that in both embodiments, the trigger is located on the barrel section of the tool for proper balance and convenience during tool operation.

The preferred embodiment of the invention also includes a detachable jig or backing die head at the muzzle end of the tool. Where tube aring operations are to be performed, the attached jig is arranged and constructed to clamp the work accurately and effectively in position, yet provide convenience in removing the tool from the work after the are has been formed.

Thus, the extremely effective Haring tool here described takes only a few seconds to load, position and discharge, and olfers convenience and efficiency in operation. It

' delivers uniform power, time after time, regardless of the operators skill, allows the operator to conveniently station himself with respect to the workpiece, and reduces operator fatigue and error by affording easy operation.

These and other objects and features of the invention will become more readily apparent from the following detailed description thereof when taken with reference to the accompanying drawings in which:

FGURE 1 is a view, in axial sectional elevation, of a tool embodying the invention as it would appear with its bolt mechanism in withdrawn position, exposing the cartridge chamber in the tool;

FIGURE 2 is a vfragmentary view similar to FIGURE l, to show the tool as it would appear with its breech closed by the bolt mechanism, and immediately after tiring the tool, whereupon the flaring instrument is at the end of its stroke;

FIGURE 3 is an enlarged axial side elevation, partially in cross-section, of the bolt member of the tool, to show the details of its construction;

FIGURE 4 is a perspective view of a tool embodying the invention, as it would appear immediately upon tiring and in the condition shown by FIGURE 2, to further show the general arrangement of the tool;

FIGURE 5 is an enlarged end view of the tool as seen in staggered cross-section viewed from lines 5 5 of FIGURE l, to show certain details of the novel, ringtype bolt sleeve of the tool;

FIGURE 6 is a perspective View of the sear link element of the tool;

FIGURE 7 is a view in cross-section taken at lines 7-7 of FGURE l, to show details of construction of the tr1gger lever and Sear link attachment in the tool;

FIGURE 8 is an enlarged fragmentary View of the receiver end portion of the tool, in axial sectional elevation as viewed from lines 8 3 of FIGURE 5, to show in detail the operable association between the trigger and firing mechanism as the parts would appear when the tool is in condition ready for ring;

FIGURE 9 is a view similar to FIGURE 8, showing the parts as they would appear immediately after the tool has been tired;

FIGURE l0 is an exploded assembly View of the breech end of the tool to show how the bolt firing mechanism is mounted in the receiver section of the tool;

FIG. 11 is a fragmentmy view in perspective of the breech of the tool with a cross-sectional fragment of the bolt tiring mechanism therewithin to show further details of the operable engagement between the bolt mechanism and receiver section;

FIGURE 12 is a fragmentary diagrammatic view of the barrel section of the tool, in axial sectional elevation, to show a modified form of the buffer system therewithin as normally arranged prior to firing the tool;

FIGURE 13 is a diagrammatic view of the butter system of FIGURE 12, as it would appear immediately after the tool has been tired, but before the flaring instrument has reached the end of its stroke;

FIGURE 14 is a diagrammatic view of the butter system of FlGURES l2 and 13 as it would appear when the flaring instrument has reached the end of its stroke;

FIGURE 15 is a fragmentary diagrammatic view of the barrel section of the tool, in axial sectional elevation, to show another modified form of the buffer system therewithin as normally arranged prior to tiring the tool;

FIG. 16 is a diagrammatic view of the butier system of FIGURE 15 as it would appear immediately after the tool has been fired, but before the flaring instrument has reached the end of its stroke;

FIGURE 17 is a diagrammatic view o the buffer system of FIGURES 15 and 16, as it would appear when the daring instrument has reached the end of its stroke;

FIGURE 18 is a fragmentary diagrammatic view of the barrel section of the tool, in axial sectional elevation, to show still another modilied forrn of the buit-er system therewithin as normally arranged prior to firing the tool;

FIGURE 19 is a diagrammatic View of the ouder sytem of FiGURE 18 as it would appear immediately after the tool has been ired, but before the flaring instrument has reached the end of its stroke;

FIGURE 2O is a diagrammatic view of the buffer system or" FIGURES 18 and 19 as it would appear when the flaring instrument has reached the end of its stroke;

FIGURE 2l is an enlarged perspective View, partially in crosssection, of a preferred form of buffer ring which forms a part of a buiier system of a tool made in accordance with the invention;

FIGURE 22 is a view similar to FIGURE 21 showing a modiiied form of buffer ring;

FIGURE 23 is a side elevation partiaLy in section, of a tool embodying the invention to show a modified form of trigger mechanism, and further to show still another modied form of buffer system, the tool in condition ready for firing; FGURE 23a is a fragmentary sectional plan View, taken at lines 23a-23a of FIGURE 23, to show certain trigger elements in greater detail;

FGURE 24 is a front elevation of the tool shown by FIGURE 23 as viewed from lines 24.-24 thereof;

FIGURE 25 is a view, in axial sectional elevation, of a tool in accordance with the invention for flaring the ends of tubing, as it would appear with its bolt mechanism in closed position ready for firing, to shown still another modification of the butter system, and a flaring instrumentality and its associated backing die head which includes clamping means, the clamping means incorporating means for curateiy positioning the tubular workpiece therein;

FIGURE 26 is a view in cross section taken generally at lines Z6- 26 of FIGURE 25, but modi'ied to show the clamping means in open position;

FIGURE 27 is a perspective view of a tubular workpiece which has a tiara-d end for ned by the tool of FIG- URE 25;

FiGURE 28 is a breakaway sectional view taken at lines 2&-25 of FIGURE 25 to show the details of the workpiece positioning device therein illustrated;

FIGURE 29 isa breakaway sectional view of the tool as generally viewed from lines 28-28 in FIGURE 25, Y

but modiiied to show a slightly different form of the workpiece positioning device therein generally illustrated, the positioning device stationed for positioning the work;

FIGURE 30 is a fragmentary side elevation, partially in section, of the flaring tool to illustrate a preferred form of workpiece positioning device incorporated in the tool;

FIGURE 31 is a sectional view taken at lines Eli-3i of FIGURE 30, to show the details of the preferred workpiece positioning device therein illustrated; and

FIGURE 32 is a sectional view taken generally at lines 252-32 of FIGURE 30, to show further details of the preferred workpiece positioning device, but modified to show the positioning device actuated to its position out of engagement with the workpiece and enabling the tool to be red.

The general arrangement of the explosively actuated daring tool provided by the invention is best described by reference to FIGURES 1 and 4. The tool has a barrel section Siti, enclosed at the muzzle end 30a of the tool by a head member which is generally indicated by numeral 31 and at the breech end 33a of the tool by a barrel closure member 32 which has formed therein an axially extending cartridge chamber 4i?. Receiver section 33 is attached to the barrel section Sti, as shown. The breech 34 of the tool is located in the receiver section 33 which has liollowed construction to receive the slidably mounted bolt tiring mechanism of the tool. The firing mechanism generally comprises a bolt member 35, a tiring pin 35 having an attached firing pin head 37, and a cylindrical firing bolt retractor, or bolt sleeve 33. The bolt sleeve 33 is attached to a handle portion 39 of the bolt member for grasping to move the bolt mechanism into and out of operable association with the cartridge chamber 4t, the forward end 41 of the bolt member 35 engaging the receiver-facing surface 42 of the closure member 355 when the tool is in condition ready for tiring.

In one preferred embodiment of the invention, as shown by FIGURES l, 2 and 4 for example, firing action is triggered by hand pressure on the longitudinally disposed trigger lever 43. By a simple squeezing or pressing motion, trigger lever 43 activates the tiring mechanism as will be seen. In another embodiment, as shown by FIGURE 23, a more conventional, but improved .fingeractuated trigger member and trigger shoe arrangement is provided, as will be described.

To minimize the possibility of the tool slipping from the hand, barrel section 3@ has a surrounding hand grip 44 which is made of vulcanized rubber-impregnated fibre, plastic, or the like and which is held in place by the lock nut 45, against the surface 46 of the trigger bracket 47. It becomes apparent that the tool is easily operated and involves the use of only one hand by the operator.

Firing of the tool will cause a flaring instrument, generally indicated in FIGURE 1 by numeral 43, to shoot forward a short distance, about an inch or more, from the muzzle of the tool into contact with the workpiece 3% upon which the flaring operation is to be performed, and to thereafter instantaneously retract it to its initial position. As shown in FIGURE 27, a tapered liare 251 will be formed on the tubular workpiece 395. Movement of the daring instrument is linear, in axial direction, through aperture 49 of the head member 3l in response to explosion of a cartridge powder charge Sti placed within chamber 4d. The expanding powder gas impels the piston 5l, which is slidable Within the barrel and at the end of which the flaring instrumentality is formed, toward the muzzle end of the tool. Piston travel, and hence the stroke of the instrument, is limited and determined by the elastically deformable buffer system of the tool, generally indicated by numeral 52, which surrounds but is slidable on the piston rod portion 53 of the flaring instrument 48. The butter system 52 elfectively extends the full length of the barrel section between the muzzlefacing, butter abutment surface 54 of the piston 51 and the buffer abutment surface S5 of the head member 31. As shown, for example by FIGURES 23 and 25, the buffer system S2 itself may not actually extend the full length of the barrel, but rather may extend between the buffer abutment surface 54 and the breech-facing end of either an energy absorbing component 202 of another type as shown in FIGURE 23, or a rigid spacer element 399 as shown in FIGURE 25, surrounding the piston rod porenr-area tion 53 between the primary buer elements and head member abutment surface 55.

As previously indicated, the head member 31 may be a clamping jig 252 as shown in FIGURES and 26. In any case, piston rod portion 53`has a flaring instrumentality, generally indicated by reference numeral 56, as its free end corresponding to work-piece contacting end 58 of haring instrument 48.

In normal position prior to tiring the tool, the end of the Haring instrumentality 56 is located a short distance away from the workpiece 395, as shown by FIG- URES 1, 23 and 25, for example. This short distance, called the stand-olf distance, permits the instrument to attain considerable velocity before striking the workpiece 305, thereby assuring its eiectiveness by utilizing the generated kinetic energy to do part of the work. Provision for standoff also serves to reduce recoil in the tool as the instrument strikes the workpiece. Such recoil would tend to be very severe if high velocity of the instrument has not been attained by the time of the impact.

The arrangement of the parts and the operation of the tool have been described generally, its construction will now be described in greater detail.

At the muzzle end a of the tool, the head member 31 may be internally threaded, as at 64, for attachment to barrel section 30 on external threads 65 thereof. Threads 64 may also be utilized to engage the lock nut 45, as shown in FIGURE 1.

Attachment of receiver section 33 to barrel section 30 is etccted by the barrel closure member 32 which has external threads 65 and 67 for engaging internal threads 68 and 69 of the barrel section and receiver section, respectively. At the junction, the closure member 32 has an annular straight surface 70 of diameter greater than that of threads 67, but less than'that of threads 65 for engagement thereover of the trigger bracket 47, usually in a press fit attachment, by its aperture surface 71. The trigger bracket 47 is a part of the trigger mechanism of the tool which also includes the trigger lever 43 (or the trigger member 2195 and its associated parts as will be described), a sear link 72 mounted for longitudinal movement on receiver section 33, and a sear 73.

For a better understanding of the preferred trigger mechanism particular reference is made to FIGURES 6 through 9 of the drawings which should be taken in conjunction with FIGURES 1, 2 and 4. It is seen that trigger bracket 47 has extending portions '74 and 75 thereof which are apertured for insertion of a transversely extending trigger pivot pin '75. The trigger lever 43 has hollowed, or inverted U-shape configuration and is apertured through its side portions, near its receiverfacing end, for pivotal connection on the pivot pin 75, as indicated, so that it extends along the barrel section 3i) on one side of the tool. Trigger lever 43 also has a receiver-surrounding sleeve portion 77 formed by the half-cylinder shaped, depending extension portions 77a thereof which are joined together, as by welding, to form a lug 78 for engaging the sear link 72 disposed on the opposite side of the tool, the lug 7S tting loosely in aperture 79 of the sear link. The sear link 72 is supported along receiver section 33 by extension of the bolt member guide pin 80 outward through the receiver section to engage the slot 81 of the sear link, as shown by FIGURE 1. A washer 82 and pin 83 of the guide pin Sti hold the Sear link in place at its mid-portion, and a transversely extending pin 84 mounted in the body of the receiver section 33, engages end slots 85 formed in upturned side portions S6 of the sear link at its receiver end to hold it in place at this end location.

A hairpin spring 87 biases the trigger lever 43 away from the barrel section 30, the spring S7 being looped, as at S8, around pivot pin 76 so that its leg portion 89 the rests against the surface of hand grip 44 and its other leg portion 90 is in pressure engagement with the underside surface of the trigger lever 43. Because of the biasing pressure, the end edge surface 91 of the trigger lever sleeve portion 77 will normally rest upon the receiver-facing end surface 92 of trigger bracket 47. As will be understood by reference to FIGURE 2, hand pressure on trigger lever 43 will urge it in clockwise direction, in the drawing, toward barrel section 30 and against the bias of spring 87, and its pivotal movement about pivot pin 75 will cause clockwise movement of receiversurrounding sleeve portion 77, and consequent substantially longitudinal movement of the lug 7 8 a short distance toward the breech end 33a of the tool. The lug 78 carries the sear link 72 in longitudinal direction toward the breech end a similar distance which is suicient to permit actuation of the sear 73 to trigger the tiring mechanisrn in the bolt member 35 in a manner to be described.

For a better understanding of the firing action of the tool, reference should first be made to the construction of the boltmember 35 and its arrangement with respect to receiver section 33. In FIGURES 3 and 10 it is shown that the bolt member 35 has a head portion 93 and a body portion 94 connected for rotation with respect to the head portion, as by straight pins 95 which tangentially engage the peripheral groove 96 of the latter. A bolt plug 97 is loosely threaded within bolt body portion 94, as by NC-Z threads 98, in a manner to permit the body portion 94 to rotate about ninety degrees with respect to the plug 97 during the cocking of the tool to its tiring condition, as will be later discussed. Bolt plug 97 has an aperture 9i therethrough for slidable passage of the tiring pin 36, and has a rectangular slot 100 to slidably receive the extended key portion 101 4of the firing pin head 37, the head 37 being firmly attached to the tiring pin 36, as by attachment pin 102. Because of the key 101 and slot 100 arrangement, the firing pin head 37, and consequently the firing pin 36, is not rotatable with respect to the bolt plug 97.

Firing pin 36 has a central body portion 163 slidable within the bore 164 of bolt head portion 93 and a pointed striker portion 105 which is axially offset from the riing pin axis so as to strike the rim of the cartridge 50 when the tool `is tired. A recess 106 is provided in the forward end 41 of the bolt member to receive the rimmed portion of the cartridge when the bolt is moved against barrel closure member 32, as previously described, and the striker portion 105 will move through aperture 197 to sharply strike and fire the cartridge 50. Such sharp, firing movement will be caused by a sudden release of compression in the main firing spring 103, as will be seen.

The main ring spring is assembled between the shouldier 199 of the tiring pin central body portion 103 and the shoulder 119 formed by the end of bolt plug 97, the bias of the spring acting against these shoulders. To assemble the bolt member 35, bolt head portion 93 and bolt body portion 94 are rst connected by appropriate press t insertion of straight pins 95. The tiring pin 36, absent liring pin head 37, is then inserted into the bore of the member, the striker portion aligned within aperture 197. Spring 108 is then inserted over the pin 36 and against shoulder 169 thereof. Next, the bolt plug 97 is iitted over the tiring pin 36 and threaded into the bolt body portion 94. The number of turns given the plug 97 on threads 98 will be sufcient to provide an appropriate stand-ofi distance of the end of the striker portion from the forward end 41 of the bolt member when the assembly has been completed. Finally, the tiring pin head 37 is attached to the firing pin 36, as by attachment pin 102, the key portion 101 thereof fitting into the solt 199 of the bolt plug 97.

As shown in FIGURES 3 and 10, the bolt body portion 94 has a notched cam surface 111 formed at a location on its end periphery, and a notched detent 113 also therein, which is in ninety-degree oiset relation with respect to the bottom of cam surface 111. When the tool has been fired, the end edge 112 of the firing pin head key portion 1&1 will lie against the bottom of the notched cam surface 111, and it becomes apparent that the tiring pin 36 may be cocked, or primed against the bias of main firing spring 168 by rotating the bolt body portion 9d ninety degrees, in counterclockwise direction with respect to the bolt head portion 93, the bolt plug 97 and, consequently, the ring pin head 37 which is keyed into plug 97 as previously described. The rotative movement between these parts forces end edge 112 to follow up the slope of the cam surface 111 and off the end thereof to rest in the notched detent 113. The enforced longitudinal movement of the firing pin head 37 withdraws ring pin 36 a short distance, causing shoulder 199 thereof to suiciently compress spring 165 against the stationary shoulder 11@ of bolt plug 97 to cock the firing mechanism.

When the bolt member 35 has been mounted in receiver section 33, this cocking action will be effected by grasping and rotating the cylindrical bolt sleeve 38 in counterclockwise direction, the bolt sleeve 38 being attached, as by screw 114, to the protruding bolt handle portion 39 which is formed on bolt body portion 94, as by brazing or welding. Thus, twisting of the sleeve 33 will twist body portion 94 with respect to both the head portion 93 and the firing pin head 37 to achieve the cooking, these members being held against rotative movement by other coacting elements. The bolt head portion 93 has a longitudinally extending slot 116 on its undersurface which slidably engages bolt member guide pin Sti to prevent its rotative movement, and the ring pin head key portion 1131 slidably engages the longitudinally extending slot 117 of the receiver section 33 to prevent its rotative movement when the tool is being cocked. On the other hand, the bolt body portion 94 has two outwardly extending guide lugs 118fz and 111th, one on each side at its head portion associated end, which slide in corresponding interior side slots 11% and 11% of the receiver section 33 as the bolt member is pushed forward for engagement of its forward end 41 with surface e2 of barrel closure member 32. The lugs 11S are free to rotate, in response to the aforesaid twisting motion, in the interior, semiircumferentially eX- tending slot 12% at the bottom of receiver section 33.

With these elements and arrangements in mind, a complete understanding of the loading, cocking and firing of the tool may now be had from the description of its operation, several additional elements to be referred to as the description proceeds. The description will first proceed on the assumption that the preferred trigger mechanism is incorporated in the tool as shown in FIGURES l, 2 and 4, for example.

Prior to the mounting the bolt member 35 within the hollowed receiver section 33, the bolt member is placed in its cocked condition, the end edge 112 of firing pin head key portion 191 resting in the notched detent 113. In this condition, guide lugs 113 of the bolt body portion will be oriented ninety degrees away from a longitudinal plane through key portion 101 so that, as the bolt member is assembled onto the receiver section, these lugs 11d slide into side slots 119 as the ey portion 1151 slides into slot 117.

The receiver section 33 has a longitudinally extending slot 121 which is offset from the bottom centerline of the receiver section, as shown in FGURE l0, for reception of a bolt stop 122 mounted therein on pin S4 and biased upwardly by a spring (not shown) into one of the interior side slots 119e of the receiver section. t/hen the bolt member 3S is assembled onto the receiver section 33, one of the guide lugs 11Sa thereof will ride over the protruding portion 125 of the bolt stop 122, momentarily forcing the bolt stop to pivot downwardly on pin 84 whereupon, when the lug 113a has passed thereover, bolt stop 122 will spring upwardly into its normal position whereat its portion 125 will prevent bolt member 3S from wholly disengaging receiver section 33 during tool operation. In operation, when the bolt member is in its withdrawn position to expose the cartridge chamber dll, its lug 118g is against protruding portion 125 of the bolt stop. Of course, to remove bolt member 35 from the receiver section, one would lift the free end of the bolt stop 122 against its spring bias sufficiently to withdraw its protrusion 125 from slot 119:1 to permit the lug 11%?1 to again pass thereover, as will be observed from a study of the drawings.

Leaving the bolt member 35 in its withdrawn position as shown by FlGURE 1, the breech 34 of the tool is open so that a blank cartridge 5h may be placed in the cartridge chamber 4t). Bolt member 35 is then pushed forward towards barrel closure member 32, closing the breech 34, the guide lugs 11S sliding within receiver section side slots 119. The protruding, cam-shaped front end of the cartridge extractor 126, which is pivotally mounted in the side of bolt head portion 93 and spring biased toward its central axis, will come into Contact with the outer edge of correspondingly cam-shaped extractor groove 127 formed in the surface 42 of closure member 32, and the forward end 41 of bolt member 35, therefore, will not be against the closure member surface 42. But, at this point, the rearward edge of guide lug 11817 will have reached the start of the downward and longitudinally directed interior cam surface 128 on the rearward edge of semicircumferentially extending interior slot 120 of the receiver section. This cam surface 12S is arranged to lead the lug 11Sb into the slot upon clockwise twisting movement being exerted on bolt 38. As the lug 11d!) travels the short distance over the cam surface 128 during a few degrees of clockwise rotation the bolt member 35 will be forced forward the short remaining distance necessary to bring its forward end 41 into abutting engagement with surface 42 of the barrel closure member, the rim of the cartridge fitting into the recess 106 of the former. rihe extractor 126, of course, will snap over the peripheral rim of the cartridge Ell into the extractor groove 127 due to its spring bias. Simultaneously, these few degrees of clockwise rotation of bolt body portion 94 will cause the end edge 112 of firing pin head key portion 191 to ride out of the notched detent 11S onto the short, flat end surface of the bolt body por-` tion 94 which lies between the detent 113 and the start of the surface track of notched end cam 111.

ln this condition, the bolt member 3S has been moved into association with the cartridge chamber 40 but the tool will not lire because end edge 112 of key portion 191 of the firing pin head is against this short end surface of bolt body portion 94 and therefore cannot travel forward in response to any trigger action of the tool to permit the firing pin 36 to strike the cartridge 5t?. Thus, a safety position of the tool has been established wherein, upon a few degrees of clockwise rotation with respect to the receiver section 33, the bolt member 35 is locked in association with the cartridge chamber yet it is impossible to ire the tool. This safety position is clearly sensed by the operator as the rearward surface of lug 118i; rides olf the forward end of cam surface 128 into slidable engagement against the rearward wall of the interior slot 126.

To place the tool in condition for firing, the bolt sleeve 3?) is further twisted in clockwise direction a full ninety degrees, which is determined by the edge 129 (FIGURES 5 and 10) of the bolt handle 39 coming into abutting contact with the edge 134B (FIGURE l) of the slot 131 in the receiver section 33, the bolt handle portion 39 riding in the peripheral slot 131. This further rotation of the bolt body portion 94 with respect to the other elements of the bolt member 35 brings its notch 111 in line with the firing pin head key portion 101 and such positioning of these parts would permit the firing pin head 37, and hence the firing pin 36 to travel a longitudinal distance equal to the depth of the notch 111 so as to fire the tool were it not for the engagement of key portion 151, by its depending angular surface 132., with the corresponding angular surface 133 of the scar 73 as shown in FIGURE 8. These surfaces are held in abutting engagement, which prevents the firing pin'36 from moving forward until the tool is triggered, by the upward biasing force exerted on the Sear 73 by its mounting spring ,134 and by the positioning of the surface portion 135 of sear link 72 under the lower surface 136 of the sear 73 when trigger lever 43 is biased by-hairpin spring S7 to its normal, pre-tiring position. It is to be noted that the biasing pressure of the sear spring 134, alone, is not suicient to prevent the movement of tiring pin head 37, and it therefore becomes apparent that firing of the tool is achieved by longitudinal movement of the sear link 72, in direction toward the breech end 33a of the tool, a distance suicient to bring its slot 137 under the lower surface 136 of the scar. Thus, when scar surface 136 rides olf the sear link surface 135 into they sear link slot 137, the biasing force of main ring spring 103 pushes the firing pin 35 forward, sharply, to strike and explode cartridge Sii, since the angular surface 132 of the key portion 101 will force the sear 73 downwardly into the slot 137 against the scar spring bias.

After the tool has been red, the bolt sleeve 38 is grasped and rotated ninety degrees in counterclockwise direction, determined by abutting engagement of the edge 133 (FGURES 5 and 10) of bolt handle portion 39 with edge 139 (FIGURES 1 and 10) of the slot 131 of the receiver section 33, to immediately again effect cocking of the firing pin S6 by forcing end edge 112 of firing pin head key portion 1611 to ride up the notched cam surface 111 to fall into the notched detent 113 at the end of the rotated bolt body portion 94. The bolt member 35 is then slidably withdrawn against the bolt stop 122, guide lugs 118 riding within side slots 119.

Simultaneously with the withdrawal movement, the extractor 126 extracts the now spent cartridge Si) from the chamber 40, pulling it outward into juxtaposition with the ejector 149 so as to be ejected from the breech 34 of the tool. Ejector 140 is longitudinally mounted in a slot 141 of the receiver section 33 by a pin 142. It is biased by ejector spring l143 into its normal position within the slot 141 and, when the bolt member 35 is withdrawn, its protruding portion 144 will be struck by the end (not shown) of the slot 145 of bolt head portion 93 in which it rides so that the ejector will be thereupon pivoted outwardly into the breech 34 into Contact with the withdrawn cartridge to eject its from the tool, as is conventional in ejector operation. The tool is now ready to be reloaded for another haring operation.

The modied trigger mechanism shown by FIGURE. 23 causes tool actuation in essentially the same manner, except that the mechanism includes the trigger link 2% and trigger 212 for finger actuation rather than the trigger lever 43 which affords hand pressure actuation. In this embodiment, the extending portions '74 and 75 and the trigger pivot pin are omitted from the trigger bracket 47. Of course, trigger lever 43, including its receiver surrounding portion 77, and thehairpin type spring 37 are also omitted. Instead, the trigger bracket 47 has a trigger guard portion 267 attached thereto which extends along the barrel section 35 of the tool towards the muzzle end 30a. The hollowed undersurface 267e of the trigger guard is spaced away from the barrel 3G to provide a passage for longitudinal movement of the trigger link 206, the side edge surfaces 2h71: of the trigger guard surrounding Vthe trigger link to contact the barrel surface for rigidity. The hand grip 44 may be slotted, as at 208, to pass around the guard portion 207 and trigger link 266, as indicated, during assembly. For greater rigidity. of attachment, trigger guard portion 207 may be additionally attached to the barrel 3@ by a band 209 near its muzzle-facing end, as shown.

At its muzzle-facing end, the trigger link 266 has a spring abutment portion 210, formed by simple, downward bending of its end portion, and a trigger cushioning spring guide member 211 attached to extend outwardly toward the muzzle end 30a of the tool. A trigger 212, of hollowed conguration, as shown in FIGURE 23a, is slidably mounted between the trigger guard 267 and the barrel section 30 (or the hand grip 44 thereof) at the muzzle-facing end of trigger link 266, slidable connection being effected by an attached slide pin 213 which rides within a longitudinally extending slot 214 of the trigger guard. A second trigger cushioning spring guide member 215 is attached within the hollow of the trigger 212 to telescope over the rst referred to guide member 211, and a trigger cushioning spring 216 biases apart the trigger 212 and the trigger link 2% by abutment against the appropriate surface of abutment portion 21() of the trigger link and spring abutment surface 217. The trigger 212 is surrounded at its forward end by sponge rubber, as at 218.

A trigger spring 219 is situated between the trigger link 206 and the trigger guard 207 to bias the trigger link towards the muzzle end 30a of the tool. This spring 219V abuts against the appropriate surface of abutment portion 215i of the trigger link, being attached thereto as by a small, straight portion 22@ of the spring being seated in a small hole 221 of the portion 216, and against trigger spring abutment means 222 on an undersurface of the trigger guard 207.

At its opposite, or breech end, the trigger link 296 is connected to the end of sear link 72, as by side notches 224 inengagement with the downwardly extending lug portions 223 of the scar link. Thus, when the trigger link 2% is moved longitudinally in direction towards the breech end 33a of the tool against the bias of trigger spring 219, it carries with it the scar link 72 to cause triggering of the tool in the same manner as has been described in connection with the preferred trigger mechanism arrangement. Trigger spring 219 effects repositioning of trigger link 266, and therefore the sear link 72, immediately after firing the tool as did the hairpin spring S7 in the previously described embodiment.

Where linger-actuation is preferred, the modified trigger mechanism effectively prevents the transmission of tool counter-recoil forces to the finger and hand of the operator. To iire the tool, the operator grasps it around the barrel hand grip 44 so that his iinger is on the sponge rubber surface 21S of the trigger 212. The location of the trigger along the barrel section 3i) is such that the tool will feel in balance when it is fired. Upon firing the tool, the tool will initially tend to recoil, or jerk rearwardly towards the operator, in response to the explosion of cartridge Sti. But the buffer system 52 and piston 51 within the barrel of the tool will bottom against the muzzle end abutment 55 almost immediately as recoil forces are initiated, as will hereinafter be more fully described, and consequent counter-recoil forces will be set up in the tool which tend to jerk it forwardly, away from the operator. A conventional, iinger-actuated trigger would transmit these recoil forces to the nger and hand, causing soreness and fatigue. However, it will be found that, by the finger-actuated trigger mechanism just described, these forces are effectively dampened by the trigger link and trigger arrangement provided which brings into play the trigger cushion spring 216. In the arrangement, the counter recoil forces will tend to be imparted to the iinger through the tendency of trigger guard 297 to move forwardly in response to counter-recoil, this member being firmly attached to the tool, and since the tool will tend to move with respect to the hand of the operator. Because the trigger 212 is against the uger of the operator, the tool is also tending to move forwardly with respect to this trigger 212. The tool may slide, or move slightly forward in the hand in response to this tendency, whereupon the movement will be against the bias of trigger cushioning spring 216, causing its compression and resulting absorption of counter-recoil forces. The telescoping spring guide members 211 and 215 assure proper action or spring 21o, and the sponge rubber 2id absorbs any excess of forces not fully absorbed by the spring 2&6. As will later become apparent, the butter system 52 reduces recoil and counter-recoil forces, per se, so that the simple trigger mechanism construction here described will be extremely eifective when incorporated within the tool or the invention.

The construction and arrangement of the novel cylindrical bolt sleeve 3S should be noted in conjunction with the results thereby afforded in the operation of the tool. lt is of a convenient diameter and length for easy grasping, and it closely surrounds the receiver section 33 when the breech 3d is closed. The sleeve 3S has a cutaway portion, as at 146, so as to be clear of sear link 72 as the sleeve is rotated, yet assure the closeness of its it around the receiver section. Further, it is made from lightweight material, such as vulcanized rubber-impregnated fibre, plastic, or the like. so as to reduce the total inertia of the tool when it is tired. lts cylindrical conliguration, and its close i'itting relationship surrounding the receiver, further balance and eliminate other inertia forces which would come into play upon firing the tool were a conventional, lever-type bolt handle to be used. For example, if a lever handle were used, its proportionately greater mass would extend outward on only one side of the tool, creating an unbalanced tool weight at the end of a lever, in effect, which, in turn, upon tiring the tool would tend to cause the tool to pivot due to the inertia of the mass and the recoil forces in the tool. Further, and as previously mentioned, immediately after initial recoil, the tool will be subject to counter-recoil which occurs when the piston bottoms, or cornes to a stop against the muzzle end abutment within the barrel of the tool, and such counter-recoil will immediately reverse the recoil forces which would have been acting upon the tool. lt is seen that the tool would be subject to erratic movement due to these forces and counter-forces, whereupon the tool would be dirhcult to control in the hands of the operator. As a result, the tool might fall from the operators hand. Provision of the cylindrical bolt sleeve 3S, instead of a conventional lever type handle, eliminates this possibihty.

Referring now to the daring instrument driver elements within the barrel section 30 of the tool, the piston 51; has a receiver-end portion 147 of considerably smaller diameter than its main body portion. In the normal condition of the tool prior to firing, the portion 147 resides within bore 48 of barrel closure member 32. The depth of the bore lf and the corresponding height of the piston portion Z447 is such that the bore volume will contain the powder gases which are generated at the instant of explosion of cartridge Sil to assure complete burning thereof before they are permitted to expand into the considerably greater diameter Stlb of the barrel section. Gf course, the piston has been initially driven forward by the explosion the distance equal to the depth of bore 143 within this instant.

As has been stated, the barrel enclosed piston rod portion 53 of punching instrument 4S is slidable through a surrounding butler system, generally indicated by numeral 52, which absorbs piston energy and brakes the piston 5l during its travel towards the muzzle end of the tool when cartridge 59 is exploded. As shown by FIGURE 2, butler system 52 is an assembly of elastically deformable buffer rings ifi? spaced by metal impact discs or rings i5@ in slidable engagement around the punching instrument shaft, or piston rod portion 53. Bilder rings 14:9 are made of neoprene, polyurethane, or similar material and have diameter considerably smaller than the diameter or interior surface tlb ,et barrel section Si). Referring to FIGURE 2l, each buffer ring 149 has a relatively thick, cylindrical shape and is centrally apertured, as at llS, for slidable passage of the piston rod portion 53 therethrough. The impact rings 15b are relatively thin and have a diameter corresponding to the diameter of interior surface Sub lllof the barrel section Siti for slidable movement therein, and are also apertured for passage of the piston rod portion 53 in the same manner as are buffer rings 154%.

As an example of a preferred embodiment of the invention, about eleven steel impact rings D and twelve buifer rings ifi-9 may be used to provide a buffer system which completely fills the barrel of the tool. The stack of rings would extend the available length of barrel section 3?, being slidably interposed between its breech end abutment surface 54, on piston 51, and its muzzle end abutment surface S5, on head member 3l. Moreover, the butler system 52 is preferably in slightly compressed condition when the piston 51 is in its normal, fully retracted position prior to tiring the tool, as shown in FGURE l. As will be understood, however, fewer or more ot either the butler rings or the impact rings, or both, may be used in the system depending on factors, such las the length of the barrel and the length of stroke of the tool, to obtain desired effects.

It is intended that when the tool is tired, the flaring instrument da will be driven forward by the piston S1 a short distance in the direction of the muzzle end 36a of the tool into contact with the workpiece. As shown by FIGURE 2, at the end of its stroke, the instrument has moved forward only an inch or so until the buffer system 5... is fully compressed, the impelling movement of the piston being in response to explosion of the cartridge 553.

The resilience of the elastically deformable buffer rings 149 causes butler system 52 to recover its normal length and arrangement within the barrel section Sil substantially instantaneously, as soon as the energy of the powder charge has been expanded. Thus, the flaring instrument 4%5 is immediately returned to its fully retracted position within barrel section 3S as soon as it as completed its H stroke.

The resiliency of the buffer rings 149 .also causes them to expand radially outward towards interior surface 3d!) of the barrel 3@ during compression of their lengths when the tool is tired. The amount of expansion is suiicient to cause frictional Contact with the barrel interior surface Slb so as to impart a braking effect between the buffer and the barrel which is in addition to the braking elfect caused by simple compression of the buder rings 149. As will be seen, other arrangements and construction of the buffer system provide a selection of braking etlects which may be obtained, the amount and nature of radial expansion of the buffer rings controlling the amount and characteristics of the total braking effect provided by the system of the piston Si.

Thus, immediate elastic recovery by the butler System of its initial, normal arrangement within the barrel of the tool causes simultaneous withdrawal of the flaring instrument from the now ilared end 251 of the tubular workpiece 365 (FlGURE 27). The full length buffer system causes prompt, full retraction of the instrument after each firing of the tool so that the tool is safely and easily handled during and between flaring operations.

Where it is `found that a greater length of instrument stroke is needed, provision for such may be incorporated in the tool simply by modifying the cross-sectional shape of the buffer rings le@ in the manner shown by FlGURE 22. The mass of each buffer ring is reduced significantly by providing peripherally chamfered oppositely disposed edge 4surfaces 152. The chamfer is considerable in its extent so that, in a barrel length of about eight inches, an additional one inch of stroke will be obtained over a buer system which includes the rings of FGURE 21, yet the same amount of energy will be absorbed by the tool and the workpiece.

As has been described, the buffer system of the invention provides a piston braking eifect during the cou-rse of its travel Vwithin the barrel. The braking effect is brought about by axial compression of the elastically deformable butter rings and also by their coincident elastic expansion inrradial direction against the interior Wall of 'f5 the barrel. It has been found that, for best results, the buffer system compression loading curve, which shows braking effect imparted to the piston and punching instrument, yis preferably linear, or nearly linear, with respect to the distance traveled.

It will be seen from consideration of FIGURES l and 2 that the arrangement and construction of the buffer system 52 shown therein will provide a curve of buffer system loading which is straight during its initial stages of cornpression, this being due to the uniform nature of axial compression of all the buffer rings 149 in sequence starting at the breech end 5d of the assembly, but that braking will begin to -be more rapidly effected as the buffer rings expand radially into contact and compressive engagement with the barrel interior surface 39h, as shown by FIG- URE 2. As a consequence, the load curve will turn sharply and increasingly upwards as the piston travels farther kalong the barrel length and as each successive ring M9 makes contact.

A greater amount of braking will be effected at earlier stages of piston travel, thus causing a straightening of the buffer system loading curve, by the modified buffer systems shown by FIGURES l2 through 20, inclusive.

In the modification shown by FIGURES 12, 13 and 14, the buffer rings 14951 towards the breech end 33a of the tool are considerably softer and therefore more compressible than are the buffer rings 1491; towards the muzzle end 39a of the tool. F or example, rings E9n may have a hardness of 50, as measured by a durometer test, whereas rings 14% may have a hardness of 75. All of the rings 14g have uniform diameter, as was the case in the embodiment shown by FIGURES 1 and 2. As will be seen from FIGURE 13, this varying hardness between groups of buffer rings causes the breech end rings 149:1 to expand radially into contact with barrel interior surface Sfib sooner than do the muzzle end rings 14%. As will be understood by those having skill in the art, the effect of this arrangement is to heighten the central zone of the loading curve, causing the total curve to be more linear. When the piston has traveled its full distance to a stop, as shown by FIGURE 14, all of the rings 149e and 1491 have expanded radially into contact with the barrel. interior surface 39h.

A similar effect can be achieved by grouping buer rings having the same hardness but different diameters. Thus, referring to FIGURES 15, 16 and 17, rings 14% towards the breech end o of the tool have greater diameter, but the same durometer hardness, as the rings 14% towards the muzzle end 3fm of the tool. As seen in FIG- URE 16, movement of the piston towards the muzzle end of the tool causes rings 149i: to contact the barrel interior surface Ib sooner than do the rings 149b. Hence, the braking effect due to radial expansion of the buffer rings occurs earlier with respect to Ipiston travel, and the loading curve of the buffer system is made more linear.

Of course, it becomes apparent that arrangements may be provided to cause any desired braking effect by varying both the hardness and diameter of one or more of the buffer rings 149 of the buffe-r system 52.

Still another modification of the buffer system is shown by FIGURES 18, 19 and 20. In this arrangement, buffer rings 1491: and 14% have the same diameters, and may or may not have the same hardness, but the buffer rings 149e are surrounded by a cylindrical brake lining 153. The lining 153 may be of rubber, or ordinary brake lining fabric, or any similar material haviang a measure of resiliency. In its normal position prior to firing the tool, the brake linings 153 has external diameter only slightly smaller than the internal diameter of the barrel. Thus, contact of the brake lining 153 with barrel interior surface 39b, due to radial expansion thereof in response to radial expansion of rings 149:1, occurs almost instaneously upon firing the tool. Braking during substantially the full travel of the piston is thereby effected, and such braking increases at a more uniform rate as each ring 149e and then each ring Ita/Wb radially expands to sequentially cause increased frictional pressure on the barrel interior surface 30h. The compression loading curve of the system will be understood to become more linear.

Consideration of the possible variations of buffer ring configuration, hardness, diameter, and effective length lead to therconclusion that buffer rings equipped with surrounding sleeves, and buffer rings having size or hardness variation in the direction of their diameters, or lengths, or both, are within the contemplation of the invention, the design of the buffer system to promote exactly Ythe desired amount and characteristics of piston braking becoming a matter of choice of these variables, once the principles of the invention are understood. The braking effect upon the piston, of course, will significantly reduce the counter-recoil shock which is experienced by the tool upon bottoming of the buffer system and piston against muzzle end abutment 55 as they come to a stop at the end of the stroke of the fia-ring instrument. The feature makes the tool more manageable by the operator since the tool will have little tendency to jerk forward, out of the operators grasp, at the instant that such bottoming occurs. But the bottoming effect `in the tool is suiiicient to counteract initial tool recoil due to the explosion of the cartridge, the two effects occurring so close in time that the initial tendency of the tool to jerk backwards toward the operator, is counteracted almost at the instant the recoil effect would become noticeable to the operator. As previously stated, the cylindrical bolt sleeve and trigger arrangement prevents tendency in the tool to twist, or otherwise move erratically when fired.

lt will be noted that buffer rings 1439s toward the breech end 33a of the tool may show wear sooner than do the rings 149!) since compression of the system occurs beginning at the breech end and the rings Iia will travel further in frictonal sliding engagement with barrel interior surface 3Q!) than rings l49b. Because of the simple, slidable mounting of the rings on the piston rod portion 53, replacement of the buffer rings of the system may be postponed and wear prolonged, by simple reversal of the order of arrangement of the rings on the rod from time to time.

A further modified form of buffer system is shown in FIGURE 23 by which different characteristics of energy absorption are obtained, and by which the distance of travel of the hole flaring instrument may be, in part, determined. For example, where a shorter stroke is desired, or where relatively soft buffer rings 149 are preferred, or where the amount of shock in the tool upon deceleration or bottoming out or' the buffer system against the muzzle end abutment surface 55 is to be reduced, a fewer number of buffer rings 149 and metal impact discs 150 may be used in a given barrel length, and an additional, relatively incompressible, energy absorbing component 292 may be assembled in tandem with the rings 149 and discs 159 also surrounding the piston rod portion 53 to fill the remaining length of the barrel. As previously referred to, the buffer system 52 is preferably assembled normally to be in slightly compressed condition. The energy absorbing component 262 comprises a plurality of elastically deformable rings 2G20. spaced by metal rings 2G21: which, in FIGURE 23, are shown mounted on piston rod portion 53 towards the muzzle end 30a of the tool, extending between the end ring 225 and abutment surface 55. The elastically deformable rings 2025: are formed of woven fabric, preferably woven nyion fibres, which are impregnated with an elastic polymer, preferably neoprene. Although relatively incompressible as compared with buffer rings 149, the rings ZGZa are sufficiently elastically deformable to absorb considerable impact energy which would otherwise be absorbed by the tool due to the high rate of deceleration of the piston 51 effected by buffer rings 149 and discs 150. This buffer system, including the shock absorbing component 2f2, will be employed, for example, in a tool intended for heavy duty use wherein a relatively greater powder 17 charge G will be exploded. If the tool is accidentally red without the flaring instrumentality 56 contacting the workpiece 305, the system will insure absorption of the excess shock which would ordinarily be absorbed by the workpiece.

It will be noted that the energy absorbing component 292 will not be axially compressed, or shortened any great extent when the tool is red, and thus also serves as an effective rigid spacer element in the buffer system of the tool whereby a shorter length of stroke of the flaring instrument will be determined. Thus, the travel of the piston 53 and punching instrument 48 assembly may be adjusted and controlled by altering the relative lengths of the series of rings M9, l5() and the series of rings 202m 202i). From the foregoing, it will be also apparent that inclusion of a rigid spacer element 300 in the buffer system 52, such as a steel cylinder of suitable length either with or without the component 2532, is witmn the contemplation of the invention. An illustration of such embodiment is shown in FGURE 25. Alternatively, a stack of steel impact rings 15d might be used as a spacer element. Of course, where the buifer system 52 is modified to include the Component 262 or the rigid spacer element 394i, it is still the highly elastically deformable nature of buffer rings 149 which accounts for full retraction of the ila/ring instrument immediately after tiring the tool.

Turning now to the construction of head member 31, and referring particularly to FIGURES 25 through 32, the head member 31 is in the form of a tube clamping jig. The clamping jig head member 31 is conveniently and removably attached to the barrel section 36, such as by appropriate internal threads 64 engaging external threads 65 of the barrel section 38. The mass of the head member provides inertia to oppose tool ring forces. The lock nut 45 locks the engagement and also holds the hand grip 44 in place. The aring instrument generally indicated by numeral 43 is formed by the piston rod portion 53 and a coneshaped flaring instrumentality 56 which is attached, as by threads 254, to the end 53 thereof. The pistonrod p0rtion 53 extends for slidable linear movement through aperture 49 of the head member. As shown in FIGURE l, the interior abutment surface 55 of head member 31 may provide the muzzle end abutment for the buffer system 52 or, alternatively and as shown in FIGURE 25, the aperture 49 may be formed in a muzzle end abutment piece 252a which is attached, as by press-fit connection 255, to the main frame portion of the clamping jig 252 as shown,- to become effectively a part thereof. The abutment piece 252z has an internal peripheral slot 256 to entrap gases and thereby provide a gas cushion to assure free slidable movement of piston rod portion 53 through the aperture 49. in this alternative construction, the muzzle end abutment surface 55a, for buffer system 52, is on the abutment piece 2525i.

The tapered work contacting surface 56a of the flaring instrumentality 56 will normally reside a short stand-off distance away from the end 25M of the tubular workpiece 395 which is to be flared so that the instrument will attain adequate velocity prior to striking the workpiece upon firing of the tool. The flaring instrumentality 56 will normally reside within a spaced recess 60 of the head member 31, which assists the operator in assuring that the predetermined proper amount of stand-off has been obtained.

The tubular workpiece 365 is clamped in position between the opposed ja vs 257 and 258, at least the upper of which (jaw 257) is slidable along the vertical guide surface 259, 260 of the clamping aperture 261 formed in the head member 31, as shown. As illustrated in FIGURE 26 which shows the clamping jig in open position, the upper jaw 257 is guided in its vertical movement with respect to the lower jaw 253 by guide rods 262, 263 located at either side of the workpiece 395, the guide rods slidable within appropriate bores 264, 265 in the upper jaw 257 and the jaws being biased apart by spring means 266, 257. The guide rods 262 and 263 may extend through appropriate bores 268, 269 in the lower jaw 258, as shown. The springs 266 and 267 engage the shoulder portions 274i, 271 formed by the widened bores 272, 273 in upper jaw 257, and also engage shoulder portions 274, 275 formed by the widened bores 276 and 277 inthe lower jaw 258. A screw type clamping pressure member 27S threadedly engages an upper frame portion 279 of the head member 3l, and engages the upper jaw 257 to exert clamping pressure thereon, as shown, so that when the member 278 is screwed downwardly, the upper jaw 257 will move downwardly against the bias of springs 256, 267 to clamp the workpiece in position for the flarinff operation. The clamping jaws 257 and 253 have grip surfaces 280 and 281, respectively, such as formed by the linely serrated saw-tooth surface pattern indicated in FIGURE 25, to rmly grip the workpiece to prevent its movement with respect to the jaws during the punching operation.

The rigid frame which forms the clamping jig head member 31 also has a muzzle end aperture 252 formed therein for passage of the tubular workpiece 355 when it is to be clamped in the jig as illustrated in the drawings. The aperture 232 has a widened portion, as indicated at 282a (FlGURE 26) so that after the are 251 has been formed on the workpiece 305, the workpiece may be conveniently removed from the head member 3l through the aperture 282 after the pressure member 27S has been backed off to release the clamping pressure on the workpiece by the clamping jaws 257, 258.

The clamping jaws 257 and 25S are made of hardened tool steel and are configured, as indicated at 283 and 284, respectively, to correspond with the taper of the surface 56a of the ilaring instrumentality 56, so that the jaws serve as a backing die against which the aring instrumentality will act when forming the flare 25?` on the workpiece. The cone shaped flaring instrumentality 56 is also made of hardened tool steel.

Vvithin the barrel section 30 the buifer system, generally indicated by numeral 52, has the elastically deformable bufer rings 149 and metal impact rings 150 arranged and constructed as previously described. In this embodiment of the invention, the buer system includes a rigid spacer element 306, such as the illustrated metal cylinder, which extends between the buffer abutment surface 55a and the metal disc 225 at the muzzle end of the buffer stack. Together with the hardness, configuration, and number of buffer rings 3.49, as previously described, inclusion of the spacer element 3Q@ will provide adjustment, depending on its length, of the length of stroke of the flaring instrument 48 in response to explosion of the cartridge 50 within the chamber 4t), yet maintain full retraction of the daring instrument upon completion of its stroke, as intended. Thus, when the tool is tired by applying hand pressure to trigger lever 43, the piston 51 is impelled forward by the expanding powder gases and causes the attached flaring instrument 4S to correspondingly move forward a predetermined short distance which is just suiiicient to form the flare 251 on the workpiece by impact of the cone shaped instrumentality 56 thereon, yet not otherwise distort or unduly stress the workpiece material, whereupon the flaring instrument 48 will instantaneously retract to its normal, pre-fired position.

The daring tool may be used to flare tubing of all practical diameter sizes and thicknesses, regardless of whether the tube material is hard or soft. Of course, the jaws 257 and 258 should correspond in diameter size with that of the tubing to be flared and in configuration to the flare to be formed. For this purpose both jaws are removable simply by disengaging the pressure member 278 from the upper yjaw 257 and sliding both jaws together with their connecting guide rods and springs, as a unit, out of the frame aperture 261 to the side of the tool, as indicated by the drawings. New jaws are then positioned on the guide rods and springs and squeezed slightly together to be conveniently and slidably reinserted in the head member 31 through frame aperture 261. Where the propersize jaws Vannexes 18 are used, automatic centering of the tubular workpiece 385 is effected.

Positioning of the tubular workpiece 305 within the clamping jig head member 31 in axial direction, so as to produce an exact length of flare thereon upon tiring of the tool, may be effected by sighting the end 251e of the workpiece, through the aperture 261, in line with the ends of the jaws 257, 258 which are generally in line with the vertical surface 268 of aperture 261. Alternatively, the end 251e of workpiece 385 may be moved against a stop provided by a workpiece positioning device such as that illustrated in two general embodiments in FIGURES 25, 28 and 29, and FlGURES 30-32, respectively, the latter being preferred.

Referring rst to FIGURES 25 and 28, one form of work positioning device 285 may be incorporated in the tool by providing a pivotable shaft 285, which is aligned in axial direction with respect to the tool and workpiece, through a bore 287 formed in the head member 3i. A workpiece stop 288 is attached at a right angle to the muzzle-facing end of the shaft 286 so as to radially depend therefrom into the recess 68 at the end of the jaw 257 to contact the end 251:1 of a tubular workpiece 305 which is to be clamped in the tool for flaring, as shown. A recess 289 is appropriately formed in the main frame of head member 31 at the top of the recess 60 to provide clearance for lateral swinging movement of the stop 288 when shaft 286 is pivoted in the manner to be described. In this connection, it should be noted that an edge portion 28% of recess 289 provides a stop to limit the amount of swinging movement of the stop 288 in direction towards its workpiece positioning station in front of the workpiece end 2:31a. Also in this regard, and particularly where small diameter tubes are to be llared using the tool, it may be necessary that the free end of the stop extend into close relationship with the cone-shaped instrumentality 56. For this purpose, the stop 288 may be appropriately beveled at its free end, as at 283:1, to conform in shape with the instrumentality 55.

At the other end of the shaft 286 of this embodiment there is attached at a right angle thereto a linger lever 220 which normally will protrude radially outwardly from the tool as shown in FlGURES 28 and 29, for example. The linger lever 298 and the stop 288 are angularly disposed with respect to the shaft 286 and with respect to each other, in a manner as shown in FIGURES 28 and 29, so that, when the lever 290 is in its referred to outwardly protruding position, the stop 288 is properly positioned inwardly of the exterior surface of the tool. As shown by FIG- URE'28, the normal position or station of the stop 288 corresponding to the normal protruding position or station of lever 298 may be such as would cause it to be out of the path of the workpiece 385, were the latter to be within the head member 31. Alternatively, as shown by FIGURE 29, the normal position of the stop 288 may be such that it lies within the path of the workpiece.

In either case, a bias spring 291 biases the stop 288 and the finger lever 290 to. their normal positions. As shown, the spring 291 is wrapped around the shaft 286 near the lever end thereof, one end of the spring bentV `290 of the workpiece positioning device 285 shown in FIGURES 25 and 28 is depressed by inger or thumb pressure against the bias of spring 291 to bring the stop 288 to its in-use position within the path of workpiece 385 at the time when it will be engaged by the tool. After the workpiece has been securely clamped within the head member, by operation of pressure member 278, the lever 290 is released whereupon the stop 288 will swing in response to the bias of spring 291 out of the path of the workpiece, and clear of the path of the flaring instrumentality 56, into its normal position. Alternatively, if the embodiment shown by FIGURE 29 is preferred, the tubular workpiece 305 may be accurately positioned in the head member 31 without any actuation of the workpiece positioning device 285 since the stop 288 is normally stationed in the path of the workpiece. It will be observed, however, that the stop 288 is also normally positioned within the path of the llaring instrumentality 56 and must be swung clear thereof before the tool is tired. Therefore, after the workpiece has been securely clamped in the tool and at the time of firing the tool, linger or thumb pressure must be exerted on the lever 290 to move it against the bias of spring 291 so as to swing the stop 288 out of the path of the instrumentality 56. After the tool has been fired, the bulfer system therein will cause the flaring instrumentality 56 to immediately retract so that the linger lever 290 may be released promptly after iiring to permit the stop 288 to swing in response to the bias of spring 291 into the path of the `tubular workpiece 305 so as to automatically be stationed for positioning the next workpiece to be ared in a subsequent tool operation.

A preferred embodiment of the workpiece positioning device 285 is shown by FIGURES 30-32. In this embodiment the workpiece stop 288 is normally stationed in the path of workpiece 305 and flaring instrumentality 56 in the same manner as was the workpiece stop in the embodiment shown by FIGURE 29. Thus, the 4tool operator cannot inadvertently clamp a workpiece 305 in the toolV without'the workpiece having been properly positioned with respect to the length of llare which will be formed thereon. However, in the preferred embodiment, any likelihood that the operator might, through inadvertence, fail to depress the lever 290 of FIGURE 29, which would move the stop 288 out of the path of the instrumentality 56 as is necessary when the tool is fired, is eliminated. This is achieved by providing a combination sleeve and cam arrangement interconnecting the workpiece positioning device 28S and the trigger lever 43 of the tool as will now be described.

In this embodiment, the shaft 286 extends through the bore 287 of the main frame of the head member 31, and the stop 288 depends from the muzzle end thereof, titting in the appropriately formed recess 289. The spring 291 is similarly arranged on the shaft 286, and biases the stop into its referred to normal position. However, the linger lever 290 of the other embodiments is eliminated and replaced by a cam follower lever 292 which extends radially from the end of the shaft 286, and has a cam follower 293 projecting therefrom to slidably engage the slot 294 of the cam protrusion 295, at the muzzle-facing end of a barrel sleeve 296 which is sleeved around the barrel section 30 of the tool for concentrically slidable movement. At the opposite end of the sleeve 296 there is a radially protruding trigger blocking stop 297 which will normally be in engagement with the underside of the lever 43 to prevent actuation and movement thereof towards the barrel 30 which would re the tool at any time when the workpiece stop 288 is within the path of flaring instrumentality 56. It will be observed from the drawings that the bias of spring 291 also causes the sleeve 296 to be biased against rotatable movement such as would permit the trigger blocking stop 297 to disengage the underside of the trigger lever 43. In other words, the spring 291 biases both the workpiece stop 288 into the path of the tubular workpiece 305 and instrumentality 56 and the trigger blocking stop 297 into engagement with the underside of the trigger lever 43, these being the normal stations of the parts.

The sleeve 295 is made of material similar to that of the hand grip 44 which normally surrounds the barrel section 30. In operating a tool which incorporates the preferred embodiment of the workpiece positioning device 285, the tool may be safely loaded prior to its engagement with a workpiece upon which a llare is to be formed since the trigger lever 43 will be blocked against its tool actuating movement. The operator moves the tubular workpiece 305 into the head member 31 of the tool between the opposed jaws 257, 25S (or alternatively moves the tool over the workpiece), whereupon the end 251a of the workpiece 305 will be moved against the stop 288 so as to be positioned to form an accurate length of are 251. The workpiece is clamped in this position by operating the pressure member 278. The operator then. grasps the barrel sleeve 296, with his fingers at the underside thereof, and rotates the sleeve a few degrees in counter-clockwise direction, as shown by FIG- URE 32, to move the trigger blocking stop 297 to the station shown in this latter figure of the drawings, whereupon the palm of the operators hand will be found to be located over the trigger lever 43 in proper position to exert squeezing pressure thereon -to re the tool. After the tool has been fired, the buffer system therein causes immediate retraction of the aring instrumentality 56 so that the operator may promptly release his grasp to permit the bias of spring 87 of the trigger lever 43 to swing the trigger lever away from the barrel 30 into its normal, pre-tired position and, substantially simultaneously, to permit the bias of spring 291 to rotate the sleeve 296 a few degrees in clockwise direction (FIGURE 32) to bring the trigger blocking stop 297 into its normal engagement with the underside of the trigger lever 43. Thus, the preferred workpiece positioning device 285, which incorporates the trigger blocking stop 297, provides a safety feature in the tool to protect the tool from damaging itself, as would happen were the tool -to be fired with the workpiece stop 28S in its normal position in the path of the instrumentality 56. As previously pointed out, normal positioning of the stop 28S in the path of the instrumentality 56 and the workpiece 305 is desirable S as to insure against inadvertence in correctly positioning the workpiece in the tool.

Thus an explosively actuated tube flaring tool has been described which achieves all of the objects ofthe invention.

We claim:

1. An explosively actuated flaring tool comprising: a barrel having a breech end and a muzzle end, barrel closure means including a cartridge receiving chamber at said breech end of the barrel, an apertured abutment member at said muzzle end of the barrel, a piston slidable Within said barrel and including an abutment surface facing towards said muzzle end of the barrel, an elongated rigid member attached to said piston to project from said piston abutment surface towards and in alignment with the aperture of said apertured abutment member for passage therethrough, said elongated rigid member terminating in a flaring tool instrumentality, buer means comprising a stacked assembly of elastically deformable buffer rings of thick rubber-like material interleaved with rigid impact rings, said buffer means slidably interposed on said elongated rigid member and eX- tending substantially the length of said barrel and engaging said piston abutment surface and said apertured abutment member, and means for tiring a cartridge within said cartridge receiving chamber, whereby said buer means substantially determines the length 0f stroke of said piston and elongated rigid member in response to the ring of such cartridge, and substantially instantaneously restores said piston and elongated rigid member to their initial positions upon completion of said stroke.

2. A aring tool according to claim 1, wherein the diameter of said buffer rings is substantially less than that of said barrel and wherein the diameter of said impact rings is but slightly less than that of said barrel 22 and such as to cause said impact rings to slide along said barrel.

3. A flaring tool according to claim 2, wherein at least one of said buffer rings has a diameter larger than other of said buffer rings.

4. A ftaring tool according to claim 2, wherein at least one of said elastically deformable buffer rings has elastic hardness characteristics differing from that of other of said buer rings.

5. A aring tool according to claim 2, wherein brake lining material is sleeved around a plurality of said buffer rings, for radial expansion therewith into contact with said barrel.

6. A flaring tool according to claim 1, wherein at least one of said elastically deformable buffer rings has peripherally chamfered oppositely disposed edge surfaces.

7. An explosively actuated daring tool according to claim 1, wherein said buffer means further comprises an additional stacked assembly of metal laminae interleaved with laminae of interlocked fibrous material impregnated with a resilient rubber-like polymer.

8. An explosively actuated Haring tool according to claim 1, wherein said apertured abutment member comprises a removable metal cylinder mounted within said barrel at its said muzzle end.

9. An explosively actuated aring tool according to claim 1 wherein-said stacked assembly of elastically deformable buffer rings is normally disposed in slightly compressed condition between said piston abutment surface and said apertured abutment member at said muzzle end of the barrel.

10. In an explosively actuated flaring tool having a longitudinally extending barrel section including a cartridge chamber and an attached receiver section mounting cartridge tiring means, the improvement comprising a trigger mechanism for said tiring means including a Sear link mounted for longitudinal slidable movement on said receiver section, an elongated hand pressure operated trigger lever extending along one side of said tool resiliently mounted for movement under pressure toward said tool, and linkage connections between said trigger lever and said sear link, whereby pressure actuation of said trigger lever actuates said ring means of the tool.

11. In an explosively actuated aring tool having a barrel section including a cartridge chamber and an attached receiver section mounting cartridge tiring means, the improvement comprising a trigger mechanism for said tiring means including a sear link mounted on said receiver section, .and a hand pressure operated trigger lever extending along said barrel section and being pivotally and resiliently mounted for movement under pressure toward said barrel section, said sear link and trigger lever being mounted on diametrically opposed sides of said tool, and said trigger having integral therewith a sleeve portion` surrounding said barrel and mechanically linked to said sear link for actuating the same in accordance with pressure actuation of said trigger lever.

12. In an explosively actuated flaring tool having a barrel section including a cartridge chamber and an attached receiver section mounting cartridge firing means, the improvement comprising a trigger mechanism for said tiring means comprising a sear link mounted on said receiver section, a trigger link mounted on said barrel section and mechanically linked to said sear link for actuating the same, a trigger mounted on said barrel section for actuating said trigger link, cushion spring means operably interposed between said trigger link and said trigger biasing the same apart, and bias means for biasing said trigger link away from said sear link.

13. In an explosively actuated flaring tool, a trigger mechanism according to claim 12, including a trigger guard attached to said barrel section enclosing said trigger link and having slot means therein for guiding a guide pin extension of said trigger, and abutment means for said bias means of said trigger link.

i4. `Arx explosively actuated aring tool comprising an enclosed barrel section having a cartridge chamber at one end and an aperture at the other end thereof, a receiver section attached to said one end of the barrel section, firing means of said tool including a withdrawable boit member slidably mounted within said receiver section for operable association with said cartridge chamber, a cylindrical sleeve portion of said bolt member for grasping to withdraw said bolt member from `said association with the cartridge chamber, a trigger mechanism of said tool including a .sear link operably engaging said firing means and a hand pressure operated trigger lever extending along one side of said tool and operably engaging said sear link, a piston displaceable within said barrel, said piston including a breech end abutment surface, a piston rod extending from said piston in axial alignment with the aperture of said barrel for passage therethrough and terminating in a daring tool instrumentality, and buffer means comprising a plurality of thick elastically deformable buffer rings spaced by substantially rigid impact rings slidably interposed on said rod and extending effectively the length of said barrel between said barrel aperture and said piston abutment surface.

15. An explosively actuated tool for aring an end of a tubular workpiece comprising an enclosed barrel section having a cartridge chamber at `one end and an aperture at the other end thereof, a receiver section attached .to said one end of the barrel section, tiring means including a withdrawable bolt member substantially surrounded by and slidably mounted within said receiver section for operable association with said cartridge chamber, a cylindrical sleeve portion of said bolt member for grasping to withdraw said bolt member from said association with the cartridge chamber and normally surrounding said receiver section when the bolt member is operably associated with said cartridge chamber, a trigger mecha nism including a sear link operably engaging said ring means and a hand pressure operated trigger lever extending longitudinally along one side of said tool and operably engaging said -sear link, a piston within said barrel section to be impelled towards said other end thereof in response to explosion of a cartridge Within said cartridge chamber, a tube flaring instrument attached to said piston extending therefrom towards said other end of the barrel section and through said aperture thereat for linear movement responsive to said movement of the piston, a buffer system within said barrel section extending eectively the length thereof between said piston and said other end of the barrel section, said buffer system comprising elastic material deformable underV compression force imparted thereto by said impelled movement of the piston whereby the buffer system determines the length of stroke of said tube Haring instrument and substantially instantaneously restores said tube flaring instrument and said piston to their initial positons wthin said barrel .section upon completion of said stroke, and a tube clamping jig at said other end of the barrel secton for clamping said tubular workpiece in axially aligned position with respect to said flaring instrument. Y

1.6. An explosively actuated tube daring tool according to claim l5, wherein said clamping "g includes opposed clamping jaw means slidably mounted therein, spring bias means biasing said jaw means in an open position to receive said workpiece, and a clamping pressure member engaging said jaw means for moving the same against the bias of said spring means to a closed position in clamping engagement with said workpiece. Y

i7. An explosively actuated tube daring tool according to claim i5, wherein said clamping jig includes releasable means forY extending into contact relationship with said end of the tubular workpiece to position the same in said jig prior to said clamping and flaring thereof, and spring bias meansl of said releasable means, said spring bias 2li means normally biasing said releasable means to a releasedposition thereof out vof the path of said Haring instrument.

E8. An explcsively actuated tube flaring tool according to ciaim l5, wherein said clamping jig includes releasable means for extending into Contact relationship with said end of the tubular workpiece to position the same in said "g prior to said clamping and flaring thereof, and spring bias means of said releasable means, said spring bias means normally biasing said releasable means to a workpiece contacting position thereof, and said releasable means having an attached stop portion extending along said barrel section normally into engagement with said trigger lever for preventing its movementresponsive to pressure thereon suihcient to re said tool.

19. An explosively actuated tool for shaping the end of a workpiece comprising an enclosed barrel section having a cartridge chamber at one end and an aperture at the other end thereof, cartridge tiring means operably associated with said cartridge chamber, a trigger mechanism for said iiring means including a hand pressure operated trigger lever extending along one side of said tool, a piston within said barrel section to be impelled toward said other end thereof in response to explosion of a cartridge within said cartridge chamber, a workpiece shaping instrument attached to said piston extending therefrom towards said other end of the barrel section for linear movement through said aperture thereat responsive to said movement of the piston, a buffer system within said barrel section adapted to Isubstantially instantaneously restore said workpiece shaping instrument to its initial ,position upon completion of a firing stroke thereof, a workpiece clamping jig at said other end of the barrel section, and a workpiece positioning device including a workpiece stop and associated bias means, said stop normally positioned and biased by said bias means into the path of said workpiece shaping instrument and movable against said bias out of said path, and means interconnecting said stop and said trigger lever lso as to normally engage the latter to prevent its tool actuating movement when said stop is in its said normal position, the last said means movable with said stop means out of said trigger lever engagement.

259. A tool according to claim 19, wherein said means interconnecting said stop and said trigger lever includes a barrel sleeve mounted for rotatablemovement on said barrel section, cam means interconnecting said barrel sleeve and workpiece stop, and a trigger lever blocking stop of said barrel sleeve.

2l. An explosively actuated flaring tool comprising an enclosed barrel section having a cartridge chamber at one end and an aperture at the other end thereof, a receiver section attached to said one end of the barrel section, firing means including a withdrawable bolt member slidably mounted within said receiver section for operable association with said cartridge chamber, a cylindrical sleeve portion of said bolt member for grasping to withdraw said bolt member from said association with the cartridge chamber and normally surrounding said receiver section when the bolt member is operably associated with said cartridge chamber, a trigger mechanism of said tool including a searflink mounted for longitudinal movement on one side of said receiver section and a hand pressure operated trigger lever disposed along said barrel section on the side thereof opposite said side of the receiver section, said trigger lever pivotally connected to said barrel section at a location along the length of said trigger lever near an end thereof for movement toward said barrel section, said trigger lever having a receiver-surrounding portion extending from said end thereof and means connecting said portion and said sear link whereby said movement of the trigger lever actuates said firing means of the tool, a piston within said barrel section to to be impelled toward said other end thereof in response to explosion of a cartridge positioned within said cartridge chamber, a 

1. AN EXPLOSIVE ACTUATED FLARING TOOL COMPREISING: A BARREL HAVING A BREECH END AND A MUZZLE END, BARREL CLOSURE MEANS INCLUDING A CARTRIDGE RECEDIVING CHAMBER AT SAID BREECH END OF THE BARREL, AN APERTURED ABUTMENT MEMBER AT SAID MUZZLE END OF THE BARREL, A PISTON SLIDABLE WITHIN SAID BARREL AND INCLUDING AN ABUTMENT SURFACE FACING TOWARDS SAID MUZZLE END OF THE BARREL, AN ELONGATED RIGID MEMBER ATTACHED TO SAID PISTON TO PROJECT FROM SAID PISTON ABUTMENT SURFACE TOWARDS AND IN ALIGNMENT WITH THE APERTURE OF SAID APERTURED ABUTMENT MEMBER FOR PASSAGE THERETHROUGH, SAID ELONGATED RIGID MEMBER TERMINATING IN A FLARING TOOL INSTRUMENTALITY, BUFFER MEANS COMPRISING A STACKED ASSEMBLY OF ELASTICALLY DEFORMABLE BUFFER RINGS OF THICK RUBBER-LIKE MATERIAL INTERLEAVED WITH RIGID IMPACT RINGS, SAID BUFFER MEANS SLIDABLY INTERPOSED ON SAID ELONGATED RIGID MEMBER AND EXTENDING SUBSTANTIALLY THE LENGTH OF SAID BARREL AND ENGAGING SAID PISTON ABUTMENT SURFACE AND SAID APERTURED ABUTMENT MEMBER, AND MEANS FOR FIRING A CARTRIDGE WITHIN SAID CARTRIDGE RECEIVING CHAMBER, WHEREBY SAID BUFFER MEANS SUBSTANTIALLY DETERMINES THE LENGTH OF STROKE OF SAID PISTON AND ELONGATED RIGID MEMBER IN RESPONSE TO THE FIRING OF SUCH CARTRIDGE, AND SUBSTANTIALLY INSTANTANEOUSLY RESTORES SAID PISTON AND ELONGATED RIGID MEMBER TO THEIR INITIAL POSITIONS UPON COMPLETION OF SAID STROKE. 